2012 Olympics | track & field finals

Team USA’s Sanya Richards-Ross celebrates after winning the gold medal in the 400 meters at the 2012 London Olympics. She won bronze in the event at Beijing.   (Wally Skalij / Los Angeles Times)

Team USA’s Sanya Richards-Ross, who was born in Jamaica, shows off an American flag after winning the gold medal in the 400 meters at the 2012 London Olympics.  (Wally Skalij / Los Angeles Times)

Team USA’s DeeDee Trotter, a Twentynine Palms native, falls to the track after winning the bronze medal in the 400 meters at the 2012 London Olympics.   (Wally Skalij / Los Angeles Times)

Justin Gatlin takes the lead in the semifinal of the 100 meters at the 2012 London Olympics on Sunday. Gatlin won gold in the event in Athens in 2004 but was unable to defend in Beijing because of a four-year ban for doping.   (Wally Skalij / Los Angeles Times)

Jamaica’s Usain Bolt, center, pulls ahead of Team USA’s Ryan Bailey, left, and Justin Gatlin to win the gold medal in the 100 meters at the 2012 London Olympics.   (Wally Skalij / Los Angeles Times)

Jamaica’s Usain Bolt, right, looks at the clock after crossing the finish line to win the gold medal in the 100 meters. Bolt also won gold in the 100-meter sprint in Beijing.   (Wally Skalij / Los Angeles Times)

Team USA’s Justin Gatlin kneels after winning the bronze in the 100 meters at the 2012 London Olympics.  (Wally Skalij / Los Angeles Times)

Jamaica’s Usain Bolt strikes a pose after winning the gold medal in the 100 meters at the 2012 London Olympics.   (Wally Skalij / Los Angeles Times)

Kenya’s Ezekiel Kemboi prays after winning the 3,000-meter steeplechase at the 2012 London Olympics. Kemboi also won the event in Athens, but came in seventh in Beijing.   (Wally Skalij / Los Angeles Times)

Kenya’s Ezekiel Kemboi jumps into the arms of France’s Mahiedine Mekhissi-Benabbad after winning the 3,000 meters steeplechase. The French runner won the silver medal.   (Wally Skalij / Los Angeles Times)